1. Technical Field
The present disclosure relates to transmission and reception methods in a cellular communication system, and more specifically, to operation methods of communication entities supporting superposition transmission in a cellular communication system.
2. Related Art
In a cellular communication system, a terminal (also referred to as ‘user equipment) may generally transmit and receive data units through a base station. For example, if there is a data unit to be transmitted to a second terminal, a first terminal may generate a message including the data unit to be transmitted to the second terminal, and transmit the generated message to the first base station. Then, the first base station may receive the message from the first terminal and identify that the destination of the received message is the second terminal. The first base station may transmit the message to a second base station to which the second terminal, the identified destination, belongs. The second base station may receive the message from the first base station and identify that the destination of the received message is the second terminal, and the second base station may transmit the message to the second terminal which is the identified destination. Finally, the second terminal may receive the message from the second base station and obtain the data unit contained in the received message.
Meanwhile, in the cellular communication system, in the case that the first terminal and the second terminal are connected to the first base station, and a first data unit to be transmitted to the first terminal and a second data unit to be transmitted to the second terminal exist in the first base station, the first base station may transmit the first data unit and the second data unit using the same resource (e.g., the same time and frequency resource). For example, when a channel state between the first base station and the first terminal is different from a channel state between the first base station and the second terminal, the first base station may transmit the first data unit and the second data unit through the same time and frequency resource by using different transmit power allocation coefficients for two terminals. Such the transmission technique may be referred to as a superposition transmission technique. In the case that such the superposition transmission technique is used, the first terminal and the second terminal may respectively acquire the first data unit and the second data unit from the first base station based on parameters required for the superposition transmission.
That is, when the superposition transmission technique is used in a cellular communication system, the parameters required for the superposition transmission should be signaled from the base station to the terminals. However, additional resources (e.g., resources for a control channel) may be required for signaling the parameters required for the superposition transmission, thereby reducing the capacity and performance of the cellular communication system.